From 01ca36685852bc5dd85fd4015c8a1e600e23e7ca Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Thu, 28 Aug 2014 09:46:10 -0500 Subject: [PATCH] tegra132: add spintable support Until PSCI is functional the other core still needs to be brought up in the kernel. The kernel boots these cpus with the spin table which is just an address in memory to monitor a jump location. BUG=chrome-os-partner:31545 BRANCH=None TEST=Built and brought up secondary core in linux. Change-Id: Ieaf19cd70aff3e6c8de932e04b1b5aba71822a97 Signed-off-by: Aaron Durbin Reviewed-on: https://chromium-review.googlesource.com/214777 Reviewed-by: Furquan Shaikh --- src/soc/nvidia/tegra132/Makefile.inc | 1 + src/soc/nvidia/tegra132/soc.c | 64 +++++++++++++++++++++++++++- src/soc/nvidia/tegra132/spintable.S | 38 +++++++++++++++++ 3 files changed, 102 insertions(+), 1 deletion(-) create mode 100644 src/soc/nvidia/tegra132/spintable.S diff --git a/src/soc/nvidia/tegra132/Makefile.inc b/src/soc/nvidia/tegra132/Makefile.inc index a36ecb8148..257d889c9f 100644 --- a/src/soc/nvidia/tegra132/Makefile.inc +++ b/src/soc/nvidia/tegra132/Makefile.inc @@ -74,6 +74,7 @@ ramstage-y += ../tegra/gpio.c ramstage-y += ../tegra/i2c.c ramstage-y += ../tegra/pinmux.c ramstage-y += ramstage.c +ramstage-y += spintable.S ramstage-y += mmu_operations.c ramstage-$(CONFIG_CONSOLE_SERIAL_UART) += uart.c ramstage-y += ../tegra/usb.c diff --git a/src/soc/nvidia/tegra132/soc.c b/src/soc/nvidia/tegra132/soc.c index 5915c0a404..6ff52248b4 100644 --- a/src/soc/nvidia/tegra132/soc.c +++ b/src/soc/nvidia/tegra132/soc.c @@ -18,10 +18,13 @@ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include #include #include #include #include +#include +#include #include #include #include @@ -59,12 +62,69 @@ static void soc_read_resources(device_t dev) static volatile int secondary_cpu_up; +static void *spintable_entry; +static uint64_t * const spintable_magic = (void *)(uintptr_t)0x80000008; + +static void spintable_init(void) +{ + extern void __wait_for_spin_table_request(void); + const size_t spintable_entry_size = 4096; + + spintable_entry = + cbmem_add(0x11111111, spintable_entry_size); + + memcpy(spintable_entry, __wait_for_spin_table_request, + spintable_entry_size); + + /* Ensure the memory location is zero'd out. */ + *spintable_magic = 0; + + dcache_clean_invalidate_by_mva(spintable_magic, + sizeof(*spintable_magic)); + dcache_clean_invalidate_by_mva(&spintable_entry, + sizeof(spintable_entry)); + dcache_clean_invalidate_by_mva(spintable_entry, spintable_entry_size); + dsb(); +} + +static void spintable_wait(void) +{ + uint32_t sctlr_el2; + uint32_t spsr_el3; + uint32_t scr_el3; + + sctlr_el2 = raw_read_sctlr_el2(); + /* Make sure EL2 is in little endian without any caching enabled. */ + sctlr_el2 &= ~(1 << 25); + sctlr_el2 &= ~(1 << 19); + sctlr_el2 &= ~(1 << 12); + sctlr_el2 &= ~0xf; + raw_write_sctlr_el2(sctlr_el2); + /* Ensure enter into EL2t with interrupts disabled. */ + spsr_el3 = (1 << 9) | (0xf << 6) | (1 << 3); + raw_write_spsr_el3(spsr_el3); + raw_write_elr_el3((uintptr_t)spintable_entry); + /* + * Lower exception level is 64 bit. HVC and SMC allowed. EL0 and EL1 + * in non-secure mode. No interrupts routed to EL3. + */ + scr_el3 = raw_read_scr_el3(); + scr_el3 |= (1 << 10) | (1 << 8) | (0x3 << 4) | (1 << 0); + scr_el3 &= ~((0x7 << 1) | (1 << 7) | (1 << 9) | (1 << 13) | (1 << 12)); + raw_write_scr_el3(scr_el3); + isb(); + asm volatile( + "mov x0, %0\n\t" + "eret\n\t" : : "r" (spintable_magic) : "x0" ); +} + void soc_secondary_cpu_init(void) { printk(BIOS_INFO, "CPU%d is up!\n", smp_processor_id()); gic_init(); dmb(); secondary_cpu_up = 1; + spintable_wait(); } static void start_secondary_cpu(void) @@ -101,8 +161,10 @@ static void soc_init(device_t dev) clock_init_arm_generic_timer(); gic_init(); - if (config->bring_up_secondary_cpu) + if (config->bring_up_secondary_cpu) { + spintable_init(); start_secondary_cpu(); + } } static void soc_noop(device_t dev) diff --git a/src/soc/nvidia/tegra132/spintable.S b/src/soc/nvidia/tegra132/spintable.S new file mode 100644 index 0000000000..3066b7e679 --- /dev/null +++ b/src/soc/nvidia/tegra132/spintable.S @@ -0,0 +1,38 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2014 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include + +ENTRY(__wait_for_spin_table_request) + /* Entry here is in EL2 with the magic address in x0. */ + mov x28, x0 +1: + ldr x27, [x28] + cmp x27, xzr + b.ne 2f + wfe + b 1b +2: + /* Entry into the kernel. */ + mov x0, xzr + mov x1, xzr + mov x2, xzr + mov x3, xzr + br x27 +ENDPROC(__wait_for_spin_table_request)